1 Julius: I've decided to take a charta from your libro, Marce, and tour the provinces. I'm going on a trip to Athenas.
2 Marcus: Ah, a beautiful city. Be warned though, the highway is being upgraded by slaves who speak Latin quite poorly. You'll notice it more as you travel closer.
3 Marcus: Strange tense changes, incorrect verb endings. But worst of all are the ways they mangle noun cases. It's sad to even think of it.
3 Julius: Oh?
4 Marcus: Yes. <sigh> The road to Hellas paved with bad declensions...

The problem with converting a phrase like "take a leaf from your book" into (pseudo-)Latin is that the word "leaf"
actually refers to a page in this context, which is a less common meaning than a leaf of a tree. Nobody
these days refers to pages as leaves, except in this cliché. So it's easy for people to get confused
and think that the cliché refers to tree leaves for some odd reason.

So when I first looked for a Latin equivalent to "leaf", I found "folium". That sounds good, and it even sounds like
it's related to paper and books, via the current English word "folio". But it actually only refers to the leaves of trees,
not the leaves of a book. Someone recommended I use either "scheda" (sheet of paper) or "charta" (sheet of papyrus)
instead. In the end I went with "charta", since papyrus is just cooler than paper.

And declension, by the way, is the modification of the form of
a noun depending on the grammatical case it takes in the sentence. And Athenae is of course a major city in
Hellas,
whose accusative form is Athenas, which I'm assured by a helpful Latin grammar Nazi is the correct case here.

2015-04-28 Rerun commentary: Actual Romans wouldn't talk about "Hell" either. For them the underworld was either Orcus or Hades or Pluto, named after one of the several gods who ruled the domain of the dead.

Unless of course they wanted to make a convoluted pun. Then all bets are off.